1. Academic Validation
  2. Upregulated mGluR5 induces ER stress and DNA damage by regulating the NMDA receptor subunit NR2B

Upregulated mGluR5 induces ER stress and DNA damage by regulating the NMDA receptor subunit NR2B

  • J Biochem. 2022 Mar 3;171(3):349-359. doi: 10.1093/jb/mvab140.
Li Gu 1 Wen-Yuan Luo 1 Ning Xia 1 2 Jian-Nan Zhang 1 Jing-Kai Fan 1 Hui-Min Yang 1 Meng-Chen Wang 3 Hong Zhang 1
Affiliations

Affiliations

  • 1 Department of Neurobiology, School of Basic Medical Sciences, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Institute for Brain Disorders, Capital Medical University, Beijing 100069, China.
  • 2 Department of Neurology, Massachusetts General Hospital, Boston, MA 02129, USA.
  • 3 School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China.
Abstract

Dysfunction caused by mGluR5 expression or activation is an important mechanism in the development of Parkinson's disease (PD). Early clinical studies on mGluR5 negative allosteric modulators have shown some limitations. It is therefore necessary to find a more specific approach to block mGluR5-mediated neurotoxicity. Here, we determined the role of N-methyl-D-aspartate (NMDA) receptor subunit NR2B in mGluR5-mediated ER stress and DNA damage. In vitro study, rotenone-induced ER stress and DNA damage were accompanied by an increase in mGluR5 expression and overexpressed or activated mGluR5 with agonist (RS)-2-chloro-5-hydroxyphenylglycine (CHPG) induced ER stress and DNA damage, while blocking mGluR5 with antagonist 2-methyl-6-(phenylethynyl) pyridine hydrochloride (MPEP) alleviated the effect. Furthermore, the damage caused by CHPG was blocked by NMDA Receptor Antagonist MK-801. Additionally, rotenone or CHPG increased the p-Src and p-NR2B, which was inhibited by MPEP. Blocking p-Src or NR2B with PP2 or CP101,606 alleviated CHPG-induced ER stress and DNA damage. Overactivation of mGluR5 accompanied with the increase of p-Src and p-NR2B in the ER stress and DNA damage was found in rotenone-induced PD rat model. These findings suggest a new mechanism wherein mGluR5 induces ER stress and DNA damage through the NMDA Receptor and propose NR2B as the molecular target for therapeutic strategy for PD.

Keywords

DNA damage; NR2B subunit; Parkinson’s disease; endoplasmic reticulum stress; metabotropic glutamate receptor 5.

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